A method of self-consistent determination of magnetic ordering in rough Fe-Cr interfaces is developed. It comprises two basic algorithms. The first algorithm is the epitaxy routine, which allows one to simulate the structure of the Fe-Cr interfaces. The epitaxy algorithm works in two variants. One of them creates relatively regular structures while the second variant generates quite irregular interfaces. The second algorithm provides a routine for determination of the magnetic ordering in a spatially inhomogeneous structure. For sets of the interfaces, constructed with the epitaxy algorithm and comprising 30 configurations, self-consistent calculations of the magnetic properties of the system are performed. This allows us to obtain the average physical quantities of the interface and its dependence on the coverage parameter with a reasonable accuracy. It is shown that low coverages of Cr upon the Fe vicinal surface cause a decrease in the average magnetic moment of the interface iron atoms. The influence of surface roughness on the smoothing of the average magnetic-moment oscillations with surface coverage is demonstrated.